Process for fiber treatment

ABSTRACT

IN AQUEOUS DISPERSION ARE USED TO IMPROVE WET STRENGTH AND WATER REPELLENCY CHARACTERISTICS OF FIBROUS MATERIALS, PARTICULARLY PAPER AND PAPER PRODUCTS.   Compositions of the formula

United States Patent n 1 Pattison Apr. 29, 1975 1 i PROCESS FOR FIBERTREATMENT [75] Inventor: Victor A. Pattison, Tonawanda.

[73] Assignee: Hooker Chemicals & Plastics C0rp., Niagara Falls, N.Y.

[22] Filed: Jan. 12,1973

[21] Appl. No.: 323,020

[56] References Cited UNITED STATES PATENTS 2.518266 3/1950 Baird et al260/295 AM 2.518267 8/1950 Baird et al 260/295 AM PrimaryExaminer-Robert L. Lindsay, .lr.

ANS/SIG!!! Examiner-William F. Smith Attorney. Agent, or FirmPeter F.Casella; John M. Petruncio [57] ABSTRACT Compositions of the formula 1 a1 ll in aqueous dispersion are used to improve wet strength and waterrepellency characteristics of fi brous materials, particularly paper andpaper products.

8 Claims, No Drawings 1 PROCESS FOR FIBER TREATMENT This inventionrelates to the treatment of fibrous materials. More particularly. thisinvention relates to the improvement of wet strength and waterrepellency properties of paper and paper products.

For many years. no commercially available wet strength resins wereavailable which would function effectively at a pH much about 5.5. i.e..on the acid side. As a consequence. many grades of paper made on thealkaline side for various reasons. including strength. softness. use ofalkaline fillers and the like. could not be effectivelywet-strengthened.

Additionally. in providing papers of wet strength and additionalproperties. such as water repellency. it has generally been found thatpaper must be treated with specific compositions to impart specificproperties. e.g.. separate conditioning agents for wet strengthening andfor water repellency.

It is an object of the present invention to provide paper and paperproducts having improved wet strength and water repellency properties.

It is another object of the present invention to provide a process forimparting wet strength and water repellancy properties to paper and topaper products by subjecting such materials to treatment with a singletreating agent.

These and other objects and advantages of the present invention willbecome apparent from a reading of the description which follows and fromthe appended claims.

It has been found that paper and paper products can be effectivelywet-strengthened and water proofed by the treatment of such materials.in acid or alkaline medium. with an aqueous dispersion of a resinousmaterial of the formula C11 a o (m N, a -G-O-R3 e J .........a (HZ l R2(R1) L b x 2 c.

as textile and paper fibers or textile and paper products. the processbeing particularly useful in treating paper pulp and paper products.

According to the process of the present invention. the fibrous materialsare treated by applying thereto the resinous materials hereinbeforespecified as aqueous dispersions. and at a pH ranging from the acidside. i.e.. lower than 7.0. to an alkaline pH. on the order of 7.5 orhigher. Generally. the dispersions contain from about 0. l to about l0percent by weight of the treating material. preferably from about 1 toabout 5 percent by weight of the treating material.

The paper pulp or paper product may be treated with the aqueousdispersion in any convenient manner. Generally. where pulp is to betreated. the dispersion is added to the pulp slurry. and the mixturestirred to effect the pulp treatment.

Desirably. the treatment is effected such that the paper has an add-onof treating material of from about 0.2 to about 2 percent by weight.based on the dry weight of the paper treated. Higher treating materialadd-on may be obtained. if desired. However. treatment to effect addonwithin the range specified is generally sufficient to provide suitablewet strength and water repellency values.

The addition of the aqueous dispersion may be conveniently effected atambient temperatures. i.e.. C. Following the contacting of the paper orpaper product with the aqueous treating dispersion. generally a periodof about minutes being sufficient to achieve the desired addon. thepaper is subjected to excess water removal. dried and cured. generallyat a temperature of about 105C for a period of about 30 to aboutminutes. in the instance where pulp is treated. the pulp is sheeted out.e.g.. as handsheets. excess water removal. and the sheets dried andcured.

The treating materials may have molecular weights on the order of fromabout 500 to about 2.500. or higher. Particularly useful are thoseresinous treating materials wherein the ratio of .r to y. the values ofwhich have been hereinbefore expressed. is about 3:2.

The resin treating materials used in the present process may be preparedby:

a. reacting N-methyl aniline. or a substituted N- methyl aniline. ormixtures of suitable Nmethyl anilines with formaldehyde and anon-N-substituted aniline. or suitable mixtures. in a condensationreaction;

b. the resin obtained from step (a) is reacted with a carbonic dihalide;

c. the resin obtained from step (b) is reacted with a C5-C aliphaticalcohol; and

d. the resin obtained from step (c) is reacted with a suitable pyridineor ring-substituted pyridine or suitable mixtures thereof.

In the formula hcreinbefore set forth. suitable R. R, and R radicalsinclude methyl. ethyl. propyl. butyl. hexyl. heptyl. octyl. decyl.phenyl. naphthyl. functional derivatives of such radicals and the like.Exemplary of suitable R radicals are pentyl. heptyl. dodecyl. stearyl.and the like, having from about 5 to about 24 carbon atoms. Thepreferred R radical is the stearyl radical l m ;n)

Suitable carbonic dihalides include phosgene. carbonic dibromide and thelike. Preferalby. the carbonic dihalide is phosgene.

Suitable N methyl anilines include, among others. N- methyl aniline;3.5-dimethyl N-methyl aniline; 4 phenyl N-methyl aniline; 3-hexylN-methyl aniline; 4-hexyl N- methyl aniline; 4-naphthyl N-methylaniline; 4-(4-chloro-phenyl)-N-methyl aniline. and the like, as well assuitable mixtures thereof. Unsubstituted N- methyl aniline is mostpreferred.

Suitable non-N-substituted anilines include 3.5- dimethyl aniline;4-phenyl aniline; 3-hexyl aniline; 3,4,5trimethyl aniline; 4-naphthylaniline and the like. as well as suitable mixtures thereof.

Suitable pyridines include 3,5 dipropyl pyridine; 3- methyl pyridine;pyridine, as well as suitable mixtures thereof. The most preferred isunsubstituted pyridine.

The formaldehyde used to prepared the resin may be obtained from suchsources as aqueous solutions of formaldehyde. trioxane paraformaldehyde,or the like.

The reaction of the alkaline compound. N-methyl aniline compound andformaldehyde is conducted by adding the formaldehyde on a continuousbasis to the aniline reactants in an acid medium, the formaldehyde addedin such amounts as to effect condensation with the anilines present.Following the addition of the formaldehyde. the reaction is madealkaline by the addition thereto of a suitable alkaline agent, such asaqueous sodium hydroxide, a solid product resulting. The liquid phase isremoved and the reaction product heated to remove any reamining water.The pH of the reaction system, during the addition of the formaldehyde.is generally maintained at l or less.

The temperature of the reaction mixture during the condensation isgenerally maintained at from about l00 to about 160C. preferably fromabout 130 to about l60C, with the condensation generally essentiallycompleted within a period of from about 60 to about 90 minutes.

The reaction product is then reacted with a selected carbonic dihalidepreferably phosgene, by adding a suitable organic solvent, heating to atemperature sufficient to remove any water present, cooling to less thanabout 35C, and adding the carbonic dihalide continuously, in aboutstoichiometric amounts, to convert the N-methyl amino groups tocarbamoyl halide groups and the amino groups to isocyanate groups. Heatis applied to move the temperature gradually up to about l50C.hydrochloric acid being evolved. The temperature is generally movedthrough a range of from about 35 to about 150C over a period of about 90minutes. The solvent is removed by distillation, generally at about 120Cunder reduced pressures. Generally the reaction is completed within aperiod of from about 90 to 120 minutes.

Suitable solvents include the halogenated hydrocarbons such aschlorobenzene, dichlorobenzene and the like.

The product of step (a) is then reacted with the selected fatty alcohol.or suitable mixtures thereof, by adding the alcohol, with stirring, tothe resin in amounts sufficient to convert essentially all of theisocyanate groups to carbamoyl ester groups, generally at a temperatureof about C. the reaction being essentially completed within a period ofabout 30 minutes. The fatty alcohols suitable for use are those havingfrom about 5 to about 24 carbon atoms, i.e., pentanol to tetra-cosanol.

The reaction product from step (c) is then reacted with the selectedpyridine compound by adding the pyridine compound in aboutstoichiometric amounts, based on the carbamoyl halide groups present.stirring and allowing the reaction mixture to stand for about 28 hours,at ambient temperatures. The reaction, however, may be conducted atelevated temperatures, on the order of about 90C.

EXAMPLE I N-methyl aniline (257 parts by weight) is condensed withformaldehyde and aniline 149 parts by weight) at a pH of about I and ata temperature of about C. The reaction mixture is added todichlorobenzene and heated to remove water present. Phosgene is added tothe reaction system, after coolin to below about 35C. and thetemperature gradually increased to about [50C over a period of about 90minutes. Following removal of the solvent, a mixture of l 5 grams oftheproduct and 43 grams of stearyl alcohol are heated at about 90C for aperiod of about 30 minutes. Pyridine (20 grams) is added to the hotreaction product and stirred for about 15 minutes until homogeneous. Thereaction system is sealed and allowed to stand an cool overnight. Theproduct is a friable wax easily dispersed in water, a 5 percent weight.

In the following examples, untreated kraft pulp is admixed with varyingconcentrations of aqueous dispersion of a resin prepared in accordancewith the procedure of Example l. After stirring for about 30 minutes.hand sheets are prepared and cured at about l05C for about 30 minutes,and conditioned overnight at about 25C and 50 percent relative humidity.The results are set forth in the following table.

TENSILE TREAT- STRENGTH MENT (Kg/15mm) EXAMPLE LEVEL I; ADDON Dr Wet '2Control 0 0 8.4 0,! l

l (Llll (M4 7.9 0.5 6 Z (1.25 0.36 7.7 (H1 8 3 (1.5 0.70 7 l l.ll l4wherein R. R and R are alkyl or aryl organic radicals. 4. A process asdefined by claim 3 wherein X is chlohaving from I to 12 carbon atoms;R;, is an alkyl radical rine. having from to 24 Carbon atoms; X ishalogen; b 5. A process as defined by claim 4 wherein the ratio and care numbers having a value of from zero to 3; .r 70 of ,t to y is about3:2. is a number having a value of from I to and is a 6. A process asdefined by claim 5 wherein the finumber from 0.8 to 4. brous materialtreated is paper pulp.

2. A process as defined by claim 1 wherein the resin- 7. A process asdefined by claim 6 wherein the resin ous material is present in theaqueous dispersion in an addon is from 0.2 to 2 percent by weight.amount of from 1 to 5 percent. H 8. Paper produced by the process asdefined by claim 3. A process as defined by claim 2 wherein a. b. and 7.c are each zero.

1. A PROCESS FOR RENDERING FIBROUS MATERIALS WETSTRENGTHENED AND WATERREPELLENT WHICH COMPRISES TREATING SAID FIBROUS MATERIAL WITH AWET-STRENGTHENING AND WATERREPELLING AMOUNT OF AN AQUEOUS DISPERSIONCOMPRISING WATER AND 0.1 TO 10 PERCENT OF AN A RESINOUS MATERIAL OF THEFORMULA
 2. A process as defined by claim 1 wherein the resinous materialis present in the aqueous dispersion in an amount of from 1 to 5percent.
 3. A process as defined by claim 2 wherein a, b, and c are eachzero.
 4. A process as defined by claim 3 wherein X is chlorine.
 5. Aprocess as defined by claim 4 wherein the ratio of x to y is about 3:2.6. A process as defined by claim 5 wherein the fibrous material treatedis paper pulp.
 7. A process as defined by claim 6 wherein the resinaddon is from 0.2 to 2 percent by weight.
 8. Paper produced by theprocess as defined by claim 7.